母亲龋易感性与婴儿口腔微生物多样性关系的纵向探究

目的通过检查有龋及无龋母亲的口腔卫生状况,并通过随访收集其婴儿1个月(1月龄)及6个月(6月龄)的唾液样本测序分析,观察母亲患龋情况对其婴儿口腔微生物多样性的影响。方法通过筛查收集1月龄婴儿的唾液样本;于首次采样时记录母亲的口腔卫生状况,根据母亲患龋情况将婴儿分为母亲有龋组(简称有龋组)和母亲无龋组(简称无龋组),跟踪随访至婴儿6个月时再次收集唾液样本。通过高通量测序的方法,分析婴儿不同月龄微生物多样性的变化。结果本研究随访受试者10例(男6例,女4例),其中有龋组7例,无龋组3例,各组间的微生物群落多样性Shannon指数均无显著性差异(P>0.05)。无龋组婴儿1月龄至6月龄时微生物群落的物种组成有较大变化;有龋组婴儿在1月龄和6月龄时组内各样本间物种组成均差异较大;1月龄时两组微生物群落较相似,而至6月龄时两组婴儿唾液的物种组成已开始发生变化。结论有龋组婴儿口腔内菌群多样性总体高于无龋组,在1月龄至6月龄间婴儿口腔内微生物物种的多样性及丰度均有了不同程度的提高。     

基于SSR标记与化学成分构建十堰地区天师栗核心种质库＊

目的 利用筛选出十堰的天师栗中高多态性SSR位点评价天师栗种质资源的遗传多样性，结合有效药用成分含量，构建十堰地区天师栗核心种质库。方法 收集十堰地区114份天师栗种质资源，以七叶树基因组为参考，采用荧光毛细管电泳筛选出高多态性SSR位点，对天师栗种质资源进行遗传多样性分析。利用HPLC测定不同种质干燥娑罗子中七叶皂苷的含量。采用最小距离逐步聚类取样策略（LDSS），根据遗传多样性保留程度初步筛选出核心种质，并对该核心种质与原始种质的遗传多样性参数进行T检验，选择与原种质差异不显著的核心种质为最佳核心种质。结果 筛选出13对高多态性SSR分子标记，遗传多样性评价结果表明十堰地区天师栗种质资源遗传多样性较高，遗传分化较小，存在着较大的基因流，114份种质资源未分为不同的亚群，周家坝和辽叶居群间具有较近的遗传亲缘关系，且周家坝居群娑罗子中的七叶皂苷A及七叶皂苷B含量普遍较高。最终筛选出的核心种质共23份，占总种质资源的20.17%，其中周家坝12份样本、辽叶6份样本、普龄5份样本。结论 将SSR分子标记与主要有效药用成分结合，采用LDSS取样策略构建十堰地区天师栗种质资源核心种质库的方法具有可行性，能够有效的保存与管理天师栗种质资源，也为当地天师栗品种改良、新品种选育研究等提供了研究基础。     

The impact of neighborhoods and friendships on interracial anxiety among medical students and residents: A report from the medical student CHANGES study

Objective

To examine the experience of interracial anxiety among health professionals and how it may affect the quality of their interactions with patients from racially marginalized populations. We explored the influence of prior interracial exposure—specifically through childhood neighborhoods, college student bodies, and friend groups—on interracial anxiety among medical students and residents. We also examined whether levels of interracial anxiety change from medical school through residency.

Data Source

Web-based longitudinal survey data from the Medical Student Cognitive Habits and Growth Evaluation Study.

Study Design

We used a retrospective longitudinal design with four observations for each trainee. The study population consisted of non-Black US medical trainees surveyed in their 1st and 4th years of medical school and 2nd and 3rd years of residency. Mixed effects longitudinal models were used to assess predictors of interracial anxiety and assess changes in interracial anxiety scores over time.

Principal Findings

In total, 3155 non-Black medical trainees were followed for 7 years. Seventy-eight percent grew up in predominantly White neighborhoods. Living in predominantly White neighborhoods and having less racially diverse friends were associated with higher levels of interracial anxiety among medical trainees. Trainees' interracial anxiety scores did not substantially change over time; interracial anxiety was highest in the 1st year of medical school, lowest in the 4th year, and increased slightly during residency.

Conclusions

Neighborhood and friend group composition had independent effects on interracial anxiety, indicating that premedical racial socialization may affect medical trainees' preparedness to interact effectively with diverse patient populations. Additionally, the lack of substantial change in interracial anxiety throughout medical training suggests the importance of providing curricular tools and structure (e.g., instituting interracial cooperative learning activities) to foster the development of healthy interracial relationships.     

69份苦玄参种质SSR遗传多样性及品质性状相关标记分析

目的:采用简单重复序列(SSR)分子标记技术对广西苦玄参主产区69份苦玄参种质样本进行遗传多样性及亲缘关系分析,并筛选与苦玄参苷含量相关联的优良种质基因。为苦玄参种质资源评价、遗传进化分析及分子标记辅助育种等提供依据。方法:基于转录组测序技术,开发20对引物进行批量扩增。利用各标记位点的遗传多态信息,分析69份苦玄参种质的遗传多样性及亲缘关系,并通过一元线性和多元逐步回归分析,筛选与苦玄参苷含量相关联的分子标记。结果:20对SSR引物共扩增出76个等位基因,平均每个位点观测等位基因3.8个,高于有效等位基因数(1.9692个),稀有等位基因率为38.2%,等位基因分布不均匀。等位基因多态率范围为0~59%,平均38.24%,各位点多态率差异较大。各位点多态信息含量(PIC)变化范围为0~0.6211,平均0.3780;Shannon多态性信息指数变化范围为0~1.2401,平均0.7590;Nei’s基因多样性指数(Nei)变化范围为0~0.6823,平均0.4409;以上3个指标最高的为P21,最低为P7,各位点遗传多样性存在较大差异。各位点平均观测杂合度为0.3824,低于平均期望杂合度(0.4425),表现为杂合子缺失;平均遗传分化系数Fst为0.3659;基因流Nm平均值为0.4332,种质遗传分化较大,基因流较小。一元线性回归分析和多元逐步回归分析结果表明,与苦玄参苷IA和IB相关的位点各有5个,其中仅有1个位点与2个成分的含量均相关。结论:20个SSR标记位点遗传多样性存在较大的差异,供试69份种质遗传分化大,基因流较小;从供试20个SSR标记中筛选出9个与苦玄参苷含量相关联的标记位点,试验结果可为苦玄参遗传进化分析及良种选育和繁育等提供依据。     

Genetic characterization and diversity of porcine circovirus type 2 in non‐vaccinated South African swine herds

The porcine circovirus type 2 (PCV2) is a swine infectious viral pathogen of great significance in global swine herds. It was recently detected at another Province of South Africa sequel to the first detection of North American‐like strain (PCV2a) at Gauteng about two decades ago, but there is a dearth of information about the genomic features and diversity of the viral strains in circulation within the country and the entire sub‐Saharan Africa region. To date, only one complete genome of the virus from South Africa is available on global data base. This current effort is therefore geared towards the full‐genome characterization of the circulating PCV2 strains in the pigs of Eastern Cape Province. With the use of conventional polymerase chain reaction method, fifteen complete PCV2 genomes were successfully amplified, sequenced and assembled from field samples obtained from non‐vaccinated pigs in the region. Neighbor Joining and Maximum Likelihood phylogenetic analyses of the ORF2 gene and full genomes unanimously showed that most of the assembled genomes (11) belong to genotype PCV2b. Furthermore, three of the characterized sequences formed clade with other reference mutant PCV2b and PCV2b subtype 1C (i.e. PCV2d) strains from the USA, China and South Korea. The last sequence, however, clustered with other reference strains belonging to PCV2 intermediate clade 2 (PCV2‐IM2), recently identified in a global PCV2 strains phylogenetic analysis. This study reports the first complete genome sequences of PCV2b, PCV2d and PCV2‐IM2 in pigs from South Africa, and it gives a possible insight into the genetic characteristics and variability of the viral strains presently in circulation within the country. It further emphasizes the need for more stringent measures in curtailing the introduction and spread of transboundary swine pathogens in the country and entire Southern African region.     

Molecular characterization of the 17D-204 yellow fever vaccine

IntroductionThe worldwide use of yellow fever (YF) live attenuated vaccines came recently under close scrutiny as rare but serious adverse events have been reported. The population identified at major risk for these safety issues were extreme ages and immunocompromised subjects. Study NCT01426243 conducted by the French National Agency for AIDS research is an ongoing interventional study to evaluate the safety of the vaccine and the specific immune responses in HIV-infected patients following 17D-204 vaccination. As a preliminary study, we characterized the molecular diversity from E gene of the single 17D-204 vaccine batch used in this clinical study.Materials and methodsEight vials of lyophilized 17D-204 vaccine (Stamaril^®, Sanofi-Pasteur, Lyon, France) of the E5499 batch were reconstituted for viral quantification, cloning and sequencing of C/prM/E region.ResultsThe average rate of virions per vial was 8.68 ± 0.07 log₁₀ genome equivalents with a low coefficient of variation (0.81%). 246 sequences of the C/prM/E region (29–33 per vials) were generated and analyzed for the eight vials, 25 (10%) being defective and excluded from analyses. 95% of sequences had at least one nucleotide mutation. The mutations were observed on 662 variant sites distributed through all over the 1995 nucleotides sequence and were mainly non-synonymous (66%). Genome variability between vaccine vials was highly homogeneous with a nucleotide distance ranging from 0.29% to 0.41%. Average p-distances observed for each vial were also homogeneous, ranging from 0.15% to 0.31%.ConclusionThis study showed a homogenous YF virus RNA quantity in vaccine vials within a single lot and a low clonal diversity inter and intra vaccine vials. These results are consistent with a recent study showing that the main mechanism of attenuation resulted in the loss of diversity in the YF virus quasi-species.     

基于高通量测序技术研究药食两用薏苡仁中污染真菌多样性

目的:调查药食两用薏苡仁中污染真菌多样性,为其安全使用提供参考依据。方法:收集薏苡仁样品18批,提取真菌DNA并扩增ITS2序列,基于Illumina MiSeq PE250平台进行高通量测序。结果:共检测到4门18纲44目99科149属的真菌,子囊菌门Ascomycota是最优势菌门,镰刀菌属Fusarium(3.05%~60.32%)是属水平最优势属,其次是曲霉属Aspergillus(2.20%~45.44%)、白僵菌属Beauveria(0.07%~63.21%)、链格孢属Alternaria(0.80%~11.92%)、Arachnomyces(0.03%~39.36%)和青霉属Penicillium(0.24%~8.03%)。此外,共检测到5种潜在产毒真菌,分别是烟曲霉A.fumigatus、土曲霉A.terreus、梨孢镰刀菌F.poae、囊状青霉P.capsulatum和展青霉P.paxilli。结论:高通量测序技术可以快速有效地检测薏苡仁中污染真菌种类,为薏苡仁污染真菌毒素提供风险预警。     

构建数字化、可视化教学平台实现妇产科学教学手段多元化

介绍了构建数字化、可视化教学平台,实现妇产科教学手段多元化的做法。内容包括多媒体课件开发制作,利用医学视听教材,建设妇产科图片数据库,建设妇产科标本库(馆),利用模型、模块进行模拟操作,加强实践技能培养和通过临床见习、实习将理论应用于实践等问题。     

The Impact of Community Diversity and Consolidated Inequality on Dropping Out of High School

Abstract: Data from the National Education Longitudinal Study were combined with census data at the zip code level to examine the impact of neighborhood racial and ethnic diversity and consolidated inequality, in addition to individual, family, and school factors, on the likelihood of dropping out of high school. Results indicate that while the effects for diversity and consolidated inequality did not support the stated hypotheses, main effects for family risk and prior academic achievement were significant and in the stated direction. Also, when controlling for individual, family, school, and neighborhood characteristics, African Americans were less likely than White students to drop out of school. Implications for contextual effects research and educational outcomes are discussed.